Merge pull request #1515 from snyk/feat/handle_aws_missing_creds

feat: Display better message when AWS credentials missing

Author: eliecharra

pkg/remote/aws/init.go

@@ -29,6 +29,10 @@ func Init(version string, alerter *alerter.Alerter,
 	if err != nil {
 		return err
 	}
+	err = provider.CheckCredentialsExist()
+	if err != nil {
+		return err
+	}
 	err = provider.Init()
 	if err != nil {
 		return err

pkg/remote/aws/provider.go

@@ -1,7 +1,9 @@
 package aws
 
 import (
+	"github.com/aws/aws-sdk-go/aws/credentials"
 	"github.com/aws/aws-sdk-go/aws/session"
+	"github.com/pkg/errors"
 	"github.com/snyk/driftctl/pkg/output"
 	"github.com/snyk/driftctl/pkg/remote/terraform"
 	tf "github.com/snyk/driftctl/pkg/terraform"
@@ -86,3 +88,16 @@ func (a *AWSTerraformProvider) Name() string {
 func (p *AWSTerraformProvider) Version() string {
 	return p.version
 }
+
+func (p *AWSTerraformProvider) CheckCredentialsExist() error {
+	_, err := p.session.Config.Credentials.Get()
+	if err == credentials.ErrNoValidProvidersFoundInChain {
+		return errors.New("Could not find a way to authenticate on AWS!\n" +
+			"Please refer to AWS documentation: https://docs.aws.amazon.com/cli/latest/userguide/cli-chap-configure.html\n\n" +
+			"To use a different cloud provider, use --to=\"tf+gcp\" for GCP or --to=\"tf+azure\" for Azure.")
+	}
+	if err != nil {
+		return err
+	}
+	return nil
+}